In Sweden, an in-service test programme has existed since before the Nordic country became an EU member in 1995.

The programme has been in place since the late-80s, said Ohlund, last week, at the 4th International Real Driving Emissions conference.

“Over the years, we have tested more than 800 vehicles”, said Ohlund, who is responsible for emission regulation for passenger cars at the Swedish Transport Agency.

The programme originally ran as part of the Swedish Environmental Protection Agency until 2004. It was then carried out by the Swedish Road Administration until Ohlund's agency took over in 2009.

What the agency did differently, from most of its European counterparts, was check the emissions performance of cars outside the scope of the legally required test.

EUobserver, the only press present at the Berlin conference, asked Ohlund why he thought other member states did not see the need for market surveillance programmes.

“Maybe it's not the need,” he said. “It's also a cost.”

Sweden spends around €2 million per year on the emissions programme, in which it tests around 75 vehicles, both passenger cars and trucks.

The source of the money: a €5 tax added to the price of every car in Sweden.

Other participants in the conference told EUobserver privately that one reason for the lack of market surveillance may be that authorities have little power over cars after they are approved.

Once a car is approved in one EU country, it is valid in the whole bloc. But only the authority which has approved the car can take action.

Since cars driving in Sweden received their certificates in another EU country, the only thing the Swedish agency could do was “ask the German authority nicely to have another look at it”, said a source who asked to remain anonymous.

The Germany Federal Motor Transport Authority (KBA) approves the most cars in all of Europe.

“That is how Europe works,” said the source. “The internal market is sacred: once a car is approved by the KBA, there is nothing left for us to do.”

In his presentation, Ohlund showed that already in 2012, the Swedes found test results from diesel cars of different types and brands that were emitting much more nitrogen oxides when they were tested in conditions different from the standard test.

“We have presented this to the Commission in various working groups for a long time,” said Per Ohlund.

But Ohlund, like other researchers in Europe, thought something was wrong with the official test method, not that carmakers had cheated.

“Maybe we did not see it as a kind of manipulation or defeat devices, but we saw it more that the regulation today is not fit for the job.”

Ohlund noted that he used his agency's result to back up the claim that a new real world driving test was needed. He said the Swedish Transport Agency is already using equipment to carry out such tests.

“We will look more outside the boundary of the type approval test,” he said.